Draw south by boat (6)
I believe the answer is:
sketch
'draw' is the definition.
(I know that sketch is a more specific form of the action draw)
'south by boat' is the wordplay.
'south' becomes 'S' (abbreviation).
'by' is a charade indicator (letters next to each other).
'boat' becomes 'ketch' (ketch is a kind of sailing vessel).
's'+'ketch'='SKETCH'
(Other definitions for sketch that I've seen before include "Rapid drawing - short play" , "Portrait" , "Dead parrot featured in one" , "Outline - preliminary drawing" , "bit of a performance" .)